Impact of reionization on CMB polarization tests of slow-roll inflation

Estimates of inflationary parameters from the CMB B-mode polarization spectrum on the largest scales depend on knowledge of the reionization history, especially at low tensor-to-scalar ratio. Assuming an incorrect reionization history in the analysis of such polarization data can strongly bias the inflationary parameters. One consequence is that the single-field slow-roll consistency relation between the tensor-to-scalar ratio and tensor tilt might be excluded with high significance even if this relation holds in reality. We explain the origin of the bias and present case studies with various tensor amplitudes and noise characteristics. A more model-independent approach can account for uncertainties about reionization, and we show that parametrizing the reionization history by a set of its principal components with respect to E-mode polarization removes the bias in inflationary parameter measurement with little degradation in precision.Comment: 9 pages, 6 figures; submitted to Phys. Rev.

On the effects of using CO2 and F2 lasers to modify the wettability of a polymeric biomaterial.

Enhancement of the surface properties of a material by means of laser radiation has been amply demonstrated previously. In this work a comparative study for the surface modification of nylon 6,6 has been conducted in order to vary the wettability characteristics using CO2 and excimer lasers. This was done by producing 50 μm spaced (with depths between 1 and 10 μm) trench-like patterns using various laser parameters such as varying the laser power for the CO2 laser and number of pulses for the excimer laser. Topographical changes were analysed using optical microscopy and white light interferometry which indicated that both laser systems can be implemented for modifying the topography of nylon 6,6. Variations in the surface chemistry were evaluated using energy-dispersive X-ray spectroscopy and x-ray photoelectron spectroscopy analysis and showed that the O2 increased by up to 1.5% At. and decreased by up to 1.6% At. for the CO2 and F2 laser patterned samples, respectively. Modification of the wettability characteristics was quantified by measuring the advancing contact angle, which was found to increase in all instances for both laser systems. Emery paper roughened samples were also analysed in the same manner to determine that the topographical pattern played a major role in the wettability characteristics of nylon 6,6. From this, it is proposed that the increase in contact angle for the laser processed samples is due to a mixed intermediate state wetting regime owed to the periodic surface roughness brought about by the laser induced trench-like topographical patterns

An Investigation of the Collective Oscillations of a Bubble Cloud

It is well known that ocean ambient noise levels in the frequency range from a few hundred hertz to several tens of kilohertz are well correlated with wind speed. A physical mechanism that could account for some of this sound generation is the production of bubble clouds by breaking waves. A simple laboratory study of the sound generated by a column of bubbles is reported here. From measurements of the various characteristics of this column, good evidence is obtained that the bubbles within the column are vibrating in a collective mode of oscillation. Based upon an assumption of collective oscillations, analytical calculations of the predicted frequency of vibration of this column as well as the dependence of this frequency on such parameters as bubble population and column geometry agree closely with the measured values. These results give evidence that the bubble plumes generated by breaking waves can be a strong source of relatively low frequency (< 1 kHz) ambient noise

The expectations and experiences of Korean international students in New Zealand Tertiary education

Korea remains the fourth largest source of international students in New Zealand, yet their numbers have halved since 2007 (Ministry of Education, 2014), raising concerns as to whether the needs and expectations of this group have been consistently met by education providers. To date, there has been little research to explore this issue, particularly in relation to tertiary study. The present study explores the reasons for Korean students coming to study in New Zealand and reports on their particular expectations and needs. The research also explores the extent to which former Korean International students in tertiary institutions have fulfilled their stated expectations. Findings are reported from face to face interviews, distance interviews and a survey of current and former international students, both male and female, in Hamilton and Auckland and in Korea. Preliminary findings indicate a general satisfaction with the quality of education and life experiences in New Zealand although some cultural adjustments presented difficulties. However, in terms of fulfilling their career goals, many reported that achieving a NZ qualification did not meet their expectations of employability. This was true for finding a job both in NZ and in Korea, with many reporting that NZ institutions had a low profile among Korean employers. The findings highlight the distinctiveness of Korean students and their particular expectations for their study and life in New Zealand. Recommendations are given for ways in which NZ tertiary providers could improve the experience and outcomes for students from this important international market. Awareness of these may help tertiary institutions in New Zealand attract and support Korean students more successfully

The expectations and experiences of Korean International Students in New Zealand tertiary education

Korea remains the fourth largest source of international students in New Zealand, yet their numbers have halved since 2007 (Ministry of Education, 2014), raising concerns as to whether the needs and expectations of this group have been consistently met by education providers. To date, there has been little research to explore this issue, particularly in relation to tertiary study. The present study explores the reasons for Korean students coming to study in New Zealand and reports on their particular expectations and needs. The research also explores the extent to which former Korean International students in tertiary institutions have fulfilled their stated expectations. Findings are reported from face to face interviews, distance interviews and a survey of current and former international students, both male and female, in Hamilton and Auckland and in Korea. Preliminary findings indicate a general satisfaction with the quality of education and life experiences in New Zealand although some cultural adjustments presented difficulties. However, in terms of fulfilling their career goals, many reported that achieving a NZ qualification did not meet their expectations of employability. This was true for finding a job both in NZ and in Korea, with many reporting that NZ institutions had a low profile among Korean employers. The findings highlight the distinctiveness of Korean students and their particular expectations for their study and life in New Zealand. Recommendations are given for ways in which NZ tertiary providers could improve the experience and outcomes for students from this important international market. Awareness of these may help tertiary institutions in New Zealand attract and support Korean students more successfully

Quasi-chemical study of Be2+^{2+}(aq) speciation

Be$^{2+}$(aq) hydrolysis can to lead to the formation of multi-beryllium clusters, but the thermodynamics of this process has not been resolved theoretically. We study the hydration state of an isolated Be$^{2+}$ ion using both the quasi-chemical theory of solutions and ab initio molecular dynamics. These studies confirm that Be$^{2+}$(aq) is tetra-hydrated. The quasi-chemical approach is then applied to then the deprotonation of Be(H_2O)_4^{2+}} to give BeOH(H_2O)_3{}^{+}}. The calculated pK$_a$ of 3.8 is in good agreement with the experimentally suggested value around 3.5. The calculated energetics for the formation of BeOHBe$^{3+}$ are then obtained in fair agreement with experiments.Comment: 11 pages, 3 figure

Increasing water cycle extremes in California and in relation to ENSO cycle under global warming

Since the winter of 2013–2014, California has experienced its most severe drought in recorded history, causing statewide water stress, severe economic loss and an extraordinary increase in wildfires. Identifying the effects of global warming on regional water cycle extremes, such as the ongoing drought in California, remains a challenge. Here we analyse large-ensemble and multi-model simulations that project the future of water cycle extremes in California as well as to understand those associations that pertain to changing climate oscillations under global warming. Both intense drought and excessive flooding are projected to increase by at least 50% towards the end of the twenty-first century; this projected increase in water cycle extremes is associated with a strengthened relation to El Niño and the Southern Oscillation (ENSO)—in particular, extreme El Niño and La Niña events that modulate California’s climate not only through its warm and cold phases but also its precursor patterns

Transformation of SV40-immortalized human uroepithelial cells by 3-methylcholanthrene increases IFN- and Large T Antigen-induced transcripts

<p>Abstract</p> <p>Background</p> <p>Simian Virus 40 (SV40) immortalization followed by treatment of cells with 3-methylcholanthrene (3-MC) has been used to elicit tumors in athymic mice. 3-MC carcinogenesis has been thoroughly studied, however gene-level interactions between 3-MC and SV40 that could have produced the observed tumors have not been explored. The commercially-available human uroepithelial cell lines were either SV40-immortalized (HUC) or SV40-immortalized and then 3-MC-transformed (HUC-TC).</p> <p>Results</p> <p>To characterize the SV40 - 3MC interaction, we compared human gene expression in these cell lines using a human cancer array and confirmed selected changes by RT-PCR. Many viral Large T Antigen (Tag) expression-related changes occurred in HUC-TC, and it is concluded that SV40 and 3-MC may act synergistically to transform cells. Changes noted in <it>IFP 9-27, 2'-5' OAS, IF 56, MxA </it>and <it>MxAB </it>were typical of those that occur in response to viral exposure and are part of the innate immune response. Because interferon is crucial to innate immune host defenses and many gene changes were interferon-related, we explored cellular growth responses to exogenous IFN-γ and found that treatment impeded growth in tumor, but not immortalized HUC on days 4 - 7. Cellular metabolism however, was inhibited in <it>both </it>cell types. We conclude that IFN-γ <it>metabolic </it>responses were functional in both cell lines, but IFN-γ <it>anti-proliferative </it>responses functioned only in tumor cells.</p> <p>Conclusions</p> <p>Synergism of SV40 with 3-MC or other environmental carcinogens may be of concern as SV40 is now endemic in 2-5.9% of the U.S. population. In addition, SV40-immortalization is a generally-accepted method used in many research materials, but the possibility of off-target effects in studies carried out using these cells has not been considered. We hope that our work will stimulate further study of this important phenomenon.</p

Estimated Time for Occurrence of Smoking-Related Consequences among Pregnant and Non-Pregnant Women

Objectives: To study time estimates by women smokers for when smoking-related consequences will occur given continuing or quitting smoking. The relationship of these estimates to pregnancy and intent to quit smoking was also investigated. Methods: Over a two-week period, eighty women, selected to constitute four subgroups formed by pregnant vs. non-pregnant and trying vs. not trying to quit smoking, rated times at which they would expect smoking-related consequences to occur given continuing or quitting smoking. Results: Somatic health consequences were estimated to occur later than consequences related to mood and social relations. All consequences were estimated to occur later given quitting smoking. Pregnancy had an effect on the estimated time that consequences would occur, with pregnant women estimating earlier occurrence of consequences related to mood and social relations than non-pregnant women did. Conclusion: Health messages should stress consequences for somatic health in quitting smoking, since outcomes later in time might have too low a value to exert a positive effect on decisions to quit smoking